title: Comparison of respiratory characteristics during enflurane and halothane anaesthesia.
abstract: The effects of enflurane on certain respiratory characteristics were compared with those of halothane in 70 patients during anaesthesia with spontaneous breathing using a specially designed circuit. The rate of respiration with enflurane (mean 22 b.p.m.) was slower than with halothane (mean 31 b.p.m.; P less than 0.001) and the tidal volume greater (enflurane mean 240 ml, halothane 180 ml; P less than 0.05). There was no statistically significant difference in the minute volume of ventilation or end-tidal carbon dioxide concentration between the two agents. The effects of a narcotic premedication were observed in 16 patients in the study. The main effect was to produce slowing of respiratory rate (enflurane mean 16 b.p.m.; halothane 18 b.p.m.). The value of the respiratory pattern compared with the measurement of heart rate and arterial pressure as a clinical guide during anaesthesia is discussed.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000769:Anesthesia, Inhalation; D002245:Carbon Dioxide; D004737:Enflurane / Q000494:pharmacology; D005260:Female; D006221:Halothane / Q000494:pharmacology; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D012119:Respiration / Q000187:drug effects*; D013147:Spirometry; D013990:Tidal Volume
chemical_list: D002245:Carbon Dioxide; D004737:Enflurane; D006221:Halothane